     (testing "the function clouseau.core/get-port."
         (is (= (get-port nil)     "3000"))
         (is (= (get-port "")      "3000"))
-        (is (= (get-port 0)       "3000"))
-        (is (= (get-port 1)       "3000"))
-        (is (= (get-port 65535)   "3000"))
-        (is (= (get-port 65536)   "3000"))))
+        (is (= (get-port -1)      "3000")) ; not a string
+        (is (= (get-port 0)       "3000")) ; not a string
+        (is (= (get-port 1)       "3000")) ; not a string
+        (is (= (get-port 65535)   "3000")) ; not a string
+        (is (= (get-port 65536)   "3000")))) ; not a string
+
+(deftest test-get-port-zero
+    "Check the function clouseau.core/get-port."
+    (testing "the function clouseau.core/get-port."
+        (is (thrown? AssertionError (get-port "0")))))
 
 (deftest test-get-port-negative
     "Check the function clouseau.core/get-port."

            (is (= {:port 3000}    (-main)))
            (is (= {:port 3000}    (-main "-1")))
            (is (= {:port 3000}    (-main "-p" "3000")))
            (is (= {:port 9999}    (-main "-p" "9999")))
            )))


;;;
;;;   Clouseau
;;; 
;;;    Copyright (C) 2015, 2016  Pavel Tisnovsky <ptisnovs@redhat.com>
;;; 
;;; Clouseau is free software; you can redistribute it and/or modify
;;; it under the terms of the GNU General Public License as published by
